One objective is to develop a reproducible synchronous transformation system for the development of T. brucei bloodstream forms into "procyclic" culture forms. A modified Hirumi cell culture system will be used to grow the blood stream trypanosomes for this study. The role of the various components of the kinetoplast DNA during this transformation process will be examined by the use of cloned fragments of KDNA maxicircles and minicircles as molecular probes. KDNA minicircles will be studied both in terms of their extreme sequence heterogeneity in this species and also in terms of any possible RNA transcripts at a specific point in the developmental process.